The S3C24xx dma does not allow more than one buffer to be enqueue prior to the dma transfers starting. This patch adds an additional parameter to s3c24xx_pcm_enqueue() to allow for passing an initial dma maximum load value.
Signed-off-by: David Anders <danders at amltd.com>
diff -urN linux-2.6.27-clean/sound/soc/s3c24xx/s3c24xx-pcm.c linux-2.6.27/sound/soc/s3c24xx/s3c24xx-pcm.c --- linux-2.6.27-clean/sound/soc/s3c24xx/s3c24xx-pcm.c 2008-11-05 08:27:23.000000000 -0600 +++ linux-2.6.27/sound/soc/s3c24xx/s3c24xx-pcm.c 2008-11-05 09:14:27.000000000 -0600 @@ -78,7 +78,8 @@ * place a dma buffer onto the queue for the dma system * to handle. */ -static void s3c24xx_pcm_enqueue(struct snd_pcm_substream *substream) +static void s3c24xx_pcm_enqueue(struct snd_pcm_substream *substream, + int dma_max) { struct s3c24xx_runtime_data *prtd = substream->runtime->private_data; dma_addr_t pos = prtd->dma_pos; @@ -86,7 +87,10 @@
DBG("Entered %s\n", __func__);
- while (prtd->dma_loaded < prtd->dma_limit) { + if (!dma_max) + dma_max = prtd->dma_limit; + + while (prtd->dma_loaded < dma_max) { unsigned long len = prtd->dma_period;
DBG("dma_loaded: %d\n", prtd->dma_loaded); @@ -132,7 +136,7 @@ spin_lock(&prtd->lock); if (prtd->state & ST_RUNNING) { prtd->dma_loaded--; - s3c24xx_pcm_enqueue(substream); + s3c24xx_pcm_enqueue(substream, 0); }
spin_unlock(&prtd->lock); @@ -249,7 +253,7 @@ prtd->dma_pos = prtd->dma_start;
/* enqueue dma buffers */ - s3c24xx_pcm_enqueue(substream); + s3c24xx_pcm_enqueue(substream, 1);
return ret; }